I'm building up a Univega Gran Sprint frame from the 80s and learning as I go. Hopefully someone can help me with a few questions:

1. I'm installing Suntour Superbe brakes, and noticed that each brake only has 1 washer paired with a nut. I assume the washer goes on the side with the nut, but do I need an additional washer on the "brake side." The rear brake mount is flat so no need for a curved washer.

2. I have Sakae Custom Road Champion handlebars, advertised with a 25.4 mm clamp area on eBay. From Sheldon's website, the common grip diameter for bars this size is 23.8 mm, but my 23.8mm Weinmann brake calipers won't slide on, no matter how loose I get them.

3. Does anyone know if a SR custom stem comes in only one stem diameter? Or if it was made in several sizes (diameter, not length)?

Thanks for any help!